1,016 research outputs found

    Graph-based software specification and verification

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    The (in)correct functioning of many software systems heavily influences how\ud we qualify our daily lives. Software companies as well as academic computer\ud science research groups spend much effort on applying and developing techniques for improving the correctness of software systems. In this dissertation\ud we focus on using and developing graph-based techniques to specify and verify\ud the behaviour of software systems in general, and object-oriented systems more\ud specifically. We elaborate on two ways to improve the correctness (and thereby\ud the quality) of such systems.\ud Firstly, we investigate the potential of using the graph transformation tech-\ud nique to formally specify the dynamic semantics of (object-oriented) program-\ud ming languages. Those semantics are typically specified in natural language.\ud Such specifications are often hard to understand or even ambiguous. We show\ud how the graph transformation framework provides formal and intuitive means\ud for their specification.\ud Secondly, we develop techniques to verify systems of which the behaviour is\ud specified as graph production systems. For the verification of such systems, we\ud introduce an algorithm that combines a well-known on-the-\ud y model checking\ud algorithm with ideas from bounded model checking. One of the main prob-\ud lems of model checking is the state-explosion problem. This problem is often\ud tackled using partial order reduction techniques. Unfortunately, many such\ud techniques are based on assumptions that do not hold for graph production sys-\ud tems. Therefore, we develop a new dynamic partial order reduction algorithm\ud based on selecting so-called probe sets and prove its correctness.\ud Most of the techniques developed in this dissertation have been implemented\ud in the graph transformation tool GROOVE

    Efficient Analysis and Synthesis of Complex Quantitative Systems

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    Tools and Algorithms for the Construction and Analysis of Systems

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    This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems

    Stochastic hybrid system : modelling and verification

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    Hybrid systems now form a classical computational paradigm unifying discrete and continuous system aspects. The modelling, analysis and verification of these systems are very difficult. One way to reduce the complexity of hybrid system models is to consider randomization. The need for stochastic models has actually multiple motivations. Usually, when building models complete information is not available and we have to consider stochastic versions. Moreover, non-determinism and uncertainty are inherent to complex systems. The stochastic approach can be thought of as a way of quantifying non-determinism (by assigning a probability to each possible execution branch) and managing uncertainty. This is built upon to the - now classical - approach in algorithmics that provides polynomial complexity algorithms via randomization. In this thesis we investigate the stochastic hybrid systems, focused on modelling and analysis. We propose a powerful unifying paradigm that combines analytical and formal methods. Its applications vary from air traffic control to communication networks and healthcare systems. The stochastic hybrid system paradigm has an explosive development. This is because of its very powerful expressivity and the great variety of possible applications. Each hybrid system model can be randomized in different ways, giving rise to many classes of stochastic hybrid systems. Moreover, randomization can change profoundly the mathematical properties of discrete and continuous aspects and also can influence their interaction. Beyond the profound foundational and semantics issues, there is the possibility to combine and cross-fertilize techniques from analytic mathematics (like optimization, control, adaptivity, stability, existence and uniqueness of trajectories, sensitivity analysis) and formal methods (like bisimulation, specification, reachability analysis, model checking). These constitute the major motivations of our research. We investigate new models of stochastic hybrid systems and their associated problems. The main difference from the existing approaches is that we do not follow one way (based only on continuous or discrete mathematics), but their cross-fertilization. For stochastic hybrid systems we introduce concepts that have been defined only for discrete transition systems. Then, techniques that have been used in discrete automata now come in a new analytical fashion. This is partly explained by the fact that popular verification methods (like theorem proving) can hardly work even on probabilistic extensions of discrete systems. When the continuous dimension is added, the idea to use continuous mathematics methods for verification purposes comes in a natural way. The concrete contribution of this thesis has four major milestones: 1. A new and a very general model for stochastic hybrid systems; 2. Stochastic reachability for stochastic hybrid systems is introduced together with an approximating method to compute reach set probabilities; 3. Bisimulation for stochastic hybrid systems is introduced and relationship with reachability analysis is investigated. 4. Considering the communication issue, we extend the modelling paradigm

    Tools and Algorithms for the Construction and Analysis of Systems

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    This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems

    Lacan\u27s Cybernetics

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    This project explores the synchronicity of psychoanalytic and cybernetic practices from the mid-to-late nineteenth century by recovery and analysis of a shared material media culture. This project takes as a starting point the work of French psychoanalyst Jacques Lacan, who observed the affinity between cybernetics and psychoanalysis, “two roughly contemporaneous techniques,” related to the emergence of the two distinct types of sciences: exact and “conjectural.” I investigate their shared patterns of figuration in the two fields, before they developed significant, and even irreconcilable, differences. This project demonstrates that what Lacan discussed explicitly in the 1950s, particularly, in his “cybernetic” Seminar II, was an expression of a more implicit connection between cybernetics and psychoanalysis ab initio. It offers a media-archaeological account of the pre-history of psychoanalysis (or proto-psychoanalytic practices) that considers the development of the psychoanalytic technique both through and against the technological mediation. The final part of this dissertation switches from the subject of the architectural and institutional panopticon of the nineteenth century to the “interpassive” user-subject of the perverse panopticon of the social media network. My discussion resonates with the current concerns expressed both within academia and in the Lacanian clinic about the degree of mediation, the limits of surveillance, the capacity of the network to exploit the subject, the automation of the gadgets that manage our lives, and the symptoms produced by all these aspects of the human-machine assemblages or even the erasure thereof in the capitalist discourse of global economy

    Metaphor and Metanoia: Linguistic Transfer and Cognitive Transformation in British and Irish Modernism

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    This dissertation contributes to the critical expansions that Douglas Mao and Rebecca L. Walkowitz identify as New Modernist Studies. This expansion is temporal, spatial, and vertical. I engage with the effects Modernist texts have “above” the page: lived experience. I examine the structural similarity of linguistic metaphor and the mind as considered by cognitive scientists. Identifying the human mind as linguistic and language as an artifact of the human mind, my research extrapolates upon what I call the “psycho-ecology” of reading, a self-representational knot between text and mind that constitutes lived experience. Far from being an abstraction, psycho-ecology is concrete: atypical textual engagement is equated with a transformation in perception. The prologue traces a lineage between Modernism, phenomenology, and the cognitive sciences. The first chapter considers the relationship between two narrative levels in Oscar Wilde’s novel The Picture of Dorian Gray (1890). The second chapter considers temporal experimentation in Virginia Woolf’s novel To the Lighthouse (1927) in relation to Martin Heidegger’s formulation of being as that which discloses our experience with language as temporal and finite. The third chapter examines the “sentimental information” of James Joyce’s Finnegans Wake (1939) from a phenomenological approach to information theory. The final chapter analyzes Samuel Beckett’s Endgame (1957) as a zero-player game that discloses the limits of agency in psycho-ecology. The dissertation follows a trajectory beginning with the intimacy a reader has with alphanumeric text towards the increasing experience of illiteracy when encountering new languages such as digital code

    Proceedings of Monterey Workshop 2001 Engineering Automation for Sofware Intensive System Integration

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    The 2001 Monterey Workshop on Engineering Automation for Software Intensive System Integration was sponsored by the Office of Naval Research, Air Force Office of Scientific Research, Army Research Office and the Defense Advance Research Projects Agency. It is our pleasure to thank the workshop advisory and sponsors for their vision of a principled engineering solution for software and for their many-year tireless effort in supporting a series of workshops to bring everyone together.This workshop is the 8 in a series of International workshops. The workshop was held in Monterey Beach Hotel, Monterey, California during June 18-22, 2001. The general theme of the workshop has been to present and discuss research works that aims at increasing the practical impact of formal methods for software and systems engineering. The particular focus of this workshop was "Engineering Automation for Software Intensive System Integration". Previous workshops have been focused on issues including, "Real-time & Concurrent Systems", "Software Merging and Slicing", "Software Evolution", "Software Architecture", "Requirements Targeting Software" and "Modeling Software System Structures in a fastly moving scenario".Office of Naval ResearchAir Force Office of Scientific Research Army Research OfficeDefense Advanced Research Projects AgencyApproved for public release, distribution unlimite
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